Knife block



FIG. 1 is a top, front, right side perspective view of a knife block, showing my new design;

FIG. 2 is a front view thereof;

FIG. 3 is a rear view thereof;

FIG. 4 is a left side view thereof;

FIG. 5 is a right side view thereof;

FIG. 6 is a top plan view thereof; and,

FIG. 7 is a bottom plan view thereof.

The broken line portions of FIG. 7 are included to show unclaimed subject matter only and form no part of the claimed design. 

CLAIM The ornamental design for a knife block, as shown and described. 